1. Field of the Invention
Forming Contoured Cushion
2. Description of the Prior Art
In numerous situations, persons are either due to infirmities or their particular occupation, required to remain seated for prolonged periods of time. Examples of such persons are patients confined to wheelchairs and in institutional environments; drivers of various types of land and airborne vehicles; assembly line workers; office workers; radar and control operators and the like. The seats provided for such persons are normally mass produced and conformed to an average contour of a person, and as a result, a person in a sitting position in a mass produced chair has substantially his entire weight supported on a few localized pressure areas. If the person is an invalid or suffering from infirmaties wherein he must remain on the mass produced chair for prolonged periods of time, the body portion in contact with the chair may suffer a breakdown of tissues or damage to nerves.
In the past a support that will conform generally to the contour of a desired portion of a patients body, has been effected by covering that portion of the body with plaster of paris bandages and holding them in a functional position for a sufficient length of time to let the plaster of paris fit. The rigid plaster of paris is then removed from the patient's body and used as a form in which to pour a plaster of paris mixture, which mixture when set will be representative of the original portion of the patient's body. This plaster of paris form may be modified at the discretion of the fitter to a desired configuration. The solidified form now has plastic applied to the exterior surface thereof, with the plaster when it is polymerized conforming to the shape of the form, and also to the shape of a portion of the patient's body. Forming a support in the above-described manner requires a high degree of skill on the part of the fitter, and as a result there is no assurance that it will conform exactly to the contour of the patient and that there will not be pressure areas on the patient's body when he is sitting or supported therein.
An operational disadvantage of the prior method of providing a patient support that will conform exactly to the contour of a desired portion of its body is that the patient is put to considerable discomfort, and due to the high degree of skill required by the fitter there may be an error in design of the finished support. Also, the providing of a patient support by the prior art method above-described requires a substantial amount of time to effect, as well as being relatively expensive.
A major object of the present invention is to provide a method of forming a contoured cushion in which the method can be carried out by a person having a minimal skill in this regard, with the finished cushion capable of being delivered to the patients in a relatively short length of time, and the cost of cushion support being sufficiently low that it may be available to practically any patient that required such a support.
The method of forming the contoured cushion is carried out by providing a pliable bag that is sealed and partially filled with expanded styrofoam pellets or other suitable material that can be readily formed. The bag containing the soft pellets is placed under the desired support area of the patient's body and moved around appropriately so that the voids between the body and the structure on which the bag will be mounted, such as a wheel chair or the like, is filled. After the pellets have moved within the confines of the bag so that they conform approximately to the contour of the patient or user sitting on the bag or having a desired portion of his body in contact with the bag, a slight vacuum is applied to the interior of the bag. When the operator is assured that the pellets have moved relative to one another to cause the external surface of the bags to truly conform to the contour of the patient's body in contact therewith, the magnitude of the vacuum in the bag is increased, and the pellets interlock with one another to become a solid mass, such interlocking being of the type that occurs in a styrofoam cup or the like. The position of the patient's body resting on the bag containing the styrofoam pellets may now be readily evacuated, with X-rays being taken to check skeletal positioning. When the appropriate pressure or shear areas of the body are relieved by the pellets and the surface of the bag most adjacent thereto being in appropriate contact with the contoured portion of the patient's body, the invention is ready for the next step in the fabrication of the patient support.
At this intermediate step in the method of forming the contour conforming support, the operator has two choices in completing the method. In the first choice, the pellet containing bag that has been contoured to conform to the body of the patient, with a vacuum still applied to the interior thereof, has a build-up of plaster or other material applied to the exterior surface of the bag to minimize ridges, bumps and creases that may be formed therein. The build up is primarily for effecting a smooth external surface on the support that will conform to the contour of the patient that will use the same, and present portions of the patient's body being subjected to undue pressure. In other words, the body of the patient will be subjected to a minimum force, when all available areas of the body of the paitent is in full contact with the external surface of the contoured support. After the build up has been completed, the pellet containing bag may have a suitable release agent applied over its surface. The bag is then wrapped with bandages that are impregnated with plaster of paris or like material. When the plaster of paris is set, the vacuum is released, and the bag with the pellets is withdrawn from the rigid shell of plaster of paris or other material that is solidified. One technique is to cut a relatively small opening through the plaster of paris shell to permit the pellets to be discharged from the interior of the bags, leaving the bags as a liner. When it is elected to remove the bag and pellets, the plaster of paris rigid shell that serves as a mold has a suitable release agent applied to the interior surface thereof. The interior of the shell that serves as a mold is then filled with a light weight material such as polyurethane and a catalyst, with the polyurethane polymerizing to a rigid mass that completely fills the interior of the shell that serves as a mold. After the polyurethane has polymerized, and has become rigid, the external shell defined by the plaster of paris impregnated bandages is removed and the core of solidified polyurethane now defining the contour conforming support for a patient or other user. A suitable covering is placed over the entire external surface of the solidified core, which covering may be a film of rubber or other material such as resin fiberglass, or the like, and the contour conforming support is now complete and ready for delivery.
The second choice of completing the method includes utilizing the pellet containing bag with vacuum still applied thereto, and the external surface of the bags being smoothed with appropriate material then the whole rigidized by applying a polyester monomer with a catalyzing agent thereto, to form a rigid shell on the exterior surface of the contoured bag. After the rigidizing material has solidified, a suitable film of a resilient material, selected rubber or the like is applied thereto, which has sufficient friction to prevent the patient or user inadvertently sliding from the completed contour conforming support. This high friction surface may not be required where patients have reasonable body control and a more appropriate surface is selected. It will be apparent from the above description that the first and second choices in completing the method may both be carried out by inexperienced personnel, and with the end product namely the contour conforming support for a patient or user being the same. In the first choice in completing the method the mold could be fed to a central fabrication area for completion. However, this process takes longer, but it eliminates the need to have supplies available at the local facility and the pellets and bags may be reused if desired. Although the methods above have been described primarily relative to the total body support system for the patient or user, it will be obvious that it may be used equally well to hold any desired portions of the body in a relatively fixed position, and with the weight of either the whole or part of the body being distributed over a maximum area of the contour conforming support. For instance, the contour conforming support may be one that is utilized in supporting the trunk, arms, hands, seating, prostheses, and other orthotic uses. The contour conforming support as above described when being formed to conform to the contour of the portions of the patient's body, is also shaped in the lower portion thereof to conform to a recessed portion in a mobile unit or a dolly, and the resulting combination serving as an inexpensive wheelchair for use in hospitals and other institutions in which the same is required either for permanent or temporary use by patients.